fawick



Feb. 14, 1956 T. FAWICK 2,734,395

DEVICE FOR DYNAMICALLY BALANCING A TUBULAR ROTARY MEMBER Filed July 5, 1952 INVENTOR. THOMAS L. FAWICK I .&

ATTORNEY VL-Flfil T i I if United States Patent cc DEVICE FOR DYNAMICALLY BALANCING A TUBULAR ROTARY MEMBER Thomas L. Fawick, Cleveland, Ohio Application July 5, 1952, Serial No. 297,37 6

3 Claims. (Cl. 74-573) This invention relates to tubular rotary members such, for example, as rolls for paper making machines, in which dynamic balance is important because the rolls rotate at high speed and usually are of such length between their bearings that bad whipping results from a condition of unbalance. Also, because of the weak and breakable character of the paper web that runs on the rolls dynamic balance is highly important.

By the use of testing methods already in extensive use it can be determined how heavy a weight must be added, and at What position within the tubular roll, to provide dynamic balance, but so far as I am aware the prevailing custom has been to drill a hole through the wall of the roll for the mounting of the weight at the proper position, and this has involved considerable expense and delay in the drilling of the hole, mounting of the weight, and refinishing the working surface of the roll at the position of the re-filled hole.

My chief objects are to avoid those disadvantages and, more specifically, to provide a weighting device adapted to be passed into the hollow roll from one of its ends and to be moved to, and secured in, the necessary position in the roll.

A further object is to provide a device that can be readily adapted to rolls of different sizes, and to rolls requiring different amounts and/or positions of weighting, by simple and inexpensive substitution and/or adjustment of parts.

Of the accompanying drawings:

Fig. 1 is a perspective view of a sectioned and brokenaway part of a roll and of one of my devices mounted in the roll.

Fig. 2 is an elevation of one of the devices as viewed in an axial direction.

Fig. 3 is a section on line 3-3 of Fig. 2.

In its preferred form shown in the present drawings, the device comprises a C-shaped strip of springy sheet metal having secured on its outer surface, as by vulcanized adhesion, a facing layer 11 of friction material such as suitably compounded rubber or, permissibly, brake-lining material. r

The ends of the C-shaped strip are bent inward in the form of hooks 12, 12 adapted to be engaged by a suitable tool, such as a long-handled pair of pliers, for springing the device to a reduced size to permit it to be freely passed into, and to the proper position in, the roll, 13, the device being of such size that it is then frictionally re tained in that position by the recoil of the strip 10 pressing 2,734,395 Patented Feb. 14, 1956 the frictional material 11 against the inner surface of the roll, when the squeezing effect of the tool is relaxed and the tool withdrawn from the roll.

Preferably at a position diametrically opposite the gap of the C, a threaded, radially disposed, weight-supporting post 14 is mounted in the metal strip 10, as by means of a conical head 15 and welding 16. Screwed upon the post 14, for radial adjustment toward and from the axis of the roll, is a weight member 17, which can be provided with a set of radially projecting turning pins 18, 18 for further adjustment of the weight after the de' vice is mounted in the roll if such further adjustment is found to be desirable.

As a simple provision for automatically holding the weight at the radial position to which it has been adjusted, the threaded post 14 is formed with a flat face 19, by simply grinding off its threads in that area, and a balldetent assembly 20 is screwed through a threaded hole, through the wall of the weight member 17, so that the spring-backed ball, riding upon the threads when the weight is turned, bears upon the flat face 19 to resist turning of the weight member from that rotative position.

It is believed that the mode of operation of the device has been adequately indicated in the foregoing description.

Various modifications are possible without departure from the scope of the invention as defined by the appended claims.

I claim:

1. A device for dynamically balancing a tubular rotary member, said device comprising an anchoring structure shaped to lie wholly within the vicinity of the inner surface of the tubular member and to engage said surface frictionally as the only support of said structure, a weightsupporting member freely and isolatedly projecting inwardly from and wholly supported by a local part of said structure, a weight mounted upon and wholly supported by said weight-supporting member, and adjusting means for securing said weight at different distances from the axis of rotation of the said rotary member.

2. A device as defined in claim 1 in which the recited weight-supporting member is a threaded post and the recited weight is threaded on said post, the device including a spring detent, dislodgable by forceful turning of the weight in relation to the post, for preventing such turning when it is not desired.

3. A device as defined in claim 1 in which the recited anchoring structure comprises a facing of frictional material for anchoring frictional engagement with the inner surface of the tubular rotary member and in which spring means is the only means for maintaining said engagement.

References Cited in the file of this patent UNITED STATES PATENTS 525,799 Rymes Sept. 11, 1894 1,138,592 Little May 4, 1915 1,305,150 Myers May 27, 1919 1,352,005 Larsson Sept. 7, 1921 l,761,023 Pontis June 3, 1930 1,768,851 Lamb July 1, 1930 2,074,290 Welsford et al. Mar. 16, 1937 

